If you are found to be eligible to take part in this study, you will receive ofatumumab up to 20 times during this study. You will receive 8 weekly infusions and then an infusion every 2 months for 2 years or until the disease gets worse. You will receive ofatumumab by vein over about 6 ½ hours the first time and over 4 hours for all the following infusions. The first infusion will be the smallest dose. The second and later infusions will be 3 times larger than the first.